A general strategy for the synthesis of α-trifluoromethyl- and α-perfluoroalkyl-β-lactams via palladium-catalyzed carbonylation

Palladium-Catalyzed Three-Component Cascade Carbonylation Reaction to Construct Benzofuran Derivatives

A novel three-component cyclization carbonylation reaction of iodoarene-tethered propargyl ethers with amine and CO is reported. This palladium-catalyzed cascade reaction undergoes a sequence of oxidative addition, unsaturated bond migration, carbonyl insertion, and nucleophilic attack to deliver the benzofuran skeleton. Both aromatic amines and aliphatic amines could proceed smoothly in this transformation under one atm of CO.

Regioselective Synthesis of 3-Trifluoromethylpyrroles by [3 + 2] Cycloaddition of N-Acyl α-Amino Acids and 2-Bromo-3,3,3-trifluoropropene

A mild and concise method for the synthesis of 3-trifluoromethylpyrroles via base-mediated [3 + 2] cycloaddition of N-acyl α-amino acids and 2-bromo-3,3,3-trifluoropropene is described. N-Acyl α-amino acids serve as 1,3-dipole precursors without additional activating agents directly. A high level of regioselectivity was observed, regardless of the electronic nature and size of the substituents on 1,3-dipoles.

Regioselective C-H Active Carbonylation via 1,4-Palladium Migration

We report a highly regioselective three-component coupling reaction of styrene, CO gas, and an amine compound to synthesize multisubstituted α,β-unsaturated amides, which involves a palladium-catalyzed sequential 1,4-palladium migration, C(sp²)-H activation, carbonylation, and amination. Salient features of this strategy include the use of 1 atm of CO, excellent stereochemistry, and good functional group tolerance. Further, a series of control experiments and density functional theory calculations were performed to afford some insights for the transfer mechanism.

Synthesis of α-CF3 Amides via Palladium-Catalyzed Carbonylation of 2-Bromo-3,3,3-trifluoropropene

Amide compounds are important organic compounds, which play an important role in biomedical chemistry, materials science, life science, and other fields. The synthesis of α-CF₃ amides, especially compounds containing 3-(trifluoromethyl)-1,3,4,5-tetrahydro-2H-benzo[b][1,4]diazepine-2-one, has long been a challenge due to the tensile properties and instability of the rings. Here, we report an example of palladium-catalyzed carbonylation of CF₃-containing olefin to form α-CF₃ acrylamide. By controlling the ligands, we can get different amide compounds as products. This method has good substrate adaptability and functional group tolerance.

Synthesis of Secondary Trifluoromethylated Alkyl Bromides Using 2-Bromo-3,3,3-trifluoropropene as a Radical Acceptor

Herein, the first example using commercially available 2-bromo-3,3,3-trifluoropropene (BTP) as a radical acceptor has been reported. Taking advantage of this strategy, a wide range of secondary trifluoromethylated alkyl bromides were synthesized in good to excellent yields with broad functional group tolerance by using redox-active esters as a radical precursor. The practicality of this protocol was further demonstrated by diverse derivations and direct modification of biologically active molecules.

Diastereoselective formation of β-lactams via a three-component reaction

A highly diastereoselective three-component reaction of N-hydroxyanilines, diazo compounds and cyclobutenones to form densely functionalized β-lactams has been realized.